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A Dose of Space

Index

1. Saturn and Jupiter may have started out with just pebbles

2. NASA finds India’s lunar orbiter after it was lost 8 years ago

3. The truth about the brightest spot of dwarf planet Ceres

4. Mars can be made habitable with an artificial magnetic field

5. SpaceX to send 2 people on a moon trip in 2018

6. A Group of 250 ancient galaxies spotted by Hubble

7. Cassini images help scientists predict the presence of global ocean on Enceladus

8. Oldest and Farthest Galaxy Discovered by Caltech Scientists

9. Astronomers discovered smallest super massive black hole in space

10. Scientists find a galaxy 13.2 billion light years from Earth

Saturn and Jupiter may have started out with just pebbles

Jupiter and Saturn are sixth and fifth planets from the sun respectively and are probably the most interesting planets in the Solar system. Saturn is widely famous for its massive rings and Jupiter, of course, for its sheer size and the number of storms that have been going on its surface for years. But they did not get to this size instantly as a new study suggests that both Jupiter and Saturn may have started off as a collection of tiny pebbles. Scientists have collected a fair amount of data from this new model and have successfully predicted that this pebble formation process can also be observed in Neptune and Uranus in the Kuiper belt where millions of icy objects are just floating that are solar system remnants.

Their existence and position from the sun also supports this theory of planetary formation. The model states that the gas-giant planets began to interact with each other once they had grown to full size. The original theory was that the ice and dust slowly amalgamated into large balls which then eventually formed the nuclei of the gas giants, Jupiter and Saturn.

The earlier theories were based on the belief that the cores of these huge planets must have been formed during the collision of fairly large bodies like rock that were nearly as big as the planets. But, once this model was inserted into a computer, it gave hundreds of Earth-sized planets into the Solar system as an output. Dr. Levison of the Southwest Research Institute in boulder, Colorado, said,” It’s widely held the first step in forming-gas giant planets – such as Jupiter and Saturn-was the production of solid cores each with a mass roughly ten times that of the Earth. If pebbles form slowly enough to allow the planetesimals to gravitationally interact with one another, the largest planetesimals have time to scatter their smaller siblings out of the disk of pebbles, thereby stifling their growth.” She further added that they showed that the leftover pebbles from the formation process, which previously were thought to be unimportant, could actually be a huge solution to the planet-forming problem.

The problems with this model is that in order to attract such a large amount of gas and dust, the core would have to be 10 times as massive as Earth and form in only a few million years. The researchers will use the pebble accretion model to see if it works in these cases or not. The gravitational instability might just explain those planets better than core accretion.

NASA finds India’s lunar orbiter after it was lost 8 years ago

Chandrayaan-1, India’s first unmanned spacecraft to moon was launched in 2008 at a cost of $79 million. It was an extremely small spacecraft, no bigger than a small car and its mission was to map the surface of the moon and survey it for precious resources. Though it was on a two year mission, Scientists in charge of it lost contact with it in 2009, August 29th 2009 was the last time the spacecraft was last in contact.

Now after eight years, NASA has located Chandrayaan-1 and it is still orbiting the moon. NASA has also located its own moon orbiter. This feat was achieved by using a new interplanetary radar technique developed by the Jet Propulsion Laboratory. NASA’s own Lunar Reconnaissance Orbiter (LRO) wasn’t hard to find as they had precise orbit data available. It was a much trickier job with Chandrayaan, as nobody knew where it is or even if it was still active, plus it is miniscule in size.

A beam of microwaves played a vital role in locating the spacecraft. The radar echoes bounced back were received by the Green Bank Telescope in West Virginia. The microwave beam was focused on the moon’s North Pole and the spacecraft passed it by multiple times over a period of three months. And NASA finally confirmed that it was indeed the lost spacecraft from India.

The truth about the brightest spot of dwarf planet Ceres

The most notable feature of the Dwarf planet Ceres is a bright spot within its central area of the Occator crater. Information gathered by NASA’s Dawn spacecraft has revealed some intriguing information about those bright spots. These bright spots are some kind of formation consisting of reflective salts. The formation is dome shaped and has been named Cerealia Facula. It has been discovered that Cerealia Facula is around 4 million years old, which is 30 million years younger than the Occator Crater.

Data was collected and analyzed using the framing camera and the visible and infrared mapping spectrometer onboard the Dawn spacecraft. Andreas Nathues at the Max Planck Institute for Solar System Research (MPS) in Gottingen led the research.

The bright shiny formation is salty by nature and is believed to be a later addition to the crater. And it might have formed over time rather than in one go. The process might have started during the massive impact that created the Occator crater. The impact may have caused briny liquid to escape to the surface. A vent system was created as methane and carbon dioxide rose to the surface. It is possible that these gases also forced carbon rich materials up on the surface which eventually formed the domed structure over time. smaller bright areas of Occator, called Vinalia Faculae, are comprised of a mixture of carbonates and dark material.

“The age and appearance of the material surrounding the bright dome indicate that Cerealia Facula was formed by a recurring, eruptive process, which also hurled material into more outward regions of the central pit”, says Andreas Nathues.

Mars can be made habitable with an artificial magnetic field

Mars is of intense interest to scientists and astronomers, but not only because it is the nearest planet to earth but also because of the colonization opportunities that it might someday provide. The planet seems to have had the make up to support life, but that has changed now. Mars magnetic field disappeared some 4.2 billion years ago, and subsequently the atmosphere began to be stripped away by solar winds.

It’s now a desolate wasteland with an atmosphere that is 100 times thinner than earth. The atmosphere is 95% carbon dioxide and 0.13% oxygen, rest is made up of nitrogen oxide, neon, hydrogen-deuterium-oxygen, krypton, and xenon. It is also much colder than earth because it is farther away from the sun.

But scientists believe that Mars can support life and colonization can be a viable option because there is a wealth of frozen water hidden under the surface of the red planet. But despite that, there are some major obstacles that need to be surmounted if colonization of Mars is ever to become a reality.

NASA has recently proposed a very ambitious project that could be a very big step towards the colonization goal. Last week at the Planetary Science Vision 2050 Workshop, NASA proposed that an artificial magnetic field be deployed around the red planet. This will safeguard the planet’s atmosphere and help it thicken over time. It will also be a barrier against the intense solar radiation.

Installation of a man made magnetic field will facilitate easier landings and will protect crews working there from most every type of radiation hazards once NASA start sending crewed missions to Mars somewhere in the next decade.

“In the future it is quite possible that an inflatable structure(s) can generate a magnetic dipole field at a level of perhaps 1 or 2 Tesla (or 10,000 to 20,000 Gauss) as an active shield against the solar wind,” Jim Green, Director of NASA’s Planetary Science Division said.

SpaceX to send 2 people on a moon trip in 2018

Elon Musk made an announcement today that SpaceX will be sending two people on a moon trip next year. And looks like, the agency has already decided who are those two lucky people. SpaceX also said that the two people paid a significant amount for this, though it refused to disclose the amount. The identities of the travelers also remains undisclosed. The space giant will start training the two later this year.

Elon said that Dragon 2 capsule will carry the passengers to the moon. The capsule is said to be powered by SpaceX’s Falcon Heavy rocket that is still under development. Before the moon trip, the agency will perform 4 missions on International Space Station. Three will transport cargo and the fourth one will carry the crew.

However, the passengers will not make a landing on moon, the rocket will circle the moon and come back to Earth. But whatever, this is going to be the furthest humans have gone into space in the last decade!

A Group of 250 ancient galaxies spotted by Hubble

Scientists are able to peek in to the history around the time of Big Bang, thanks to Hubble telescope. It has spotted a collection of 250 tiny ancient galaxies. The Hubble space telescope has been operating since 1990 and still continues to amaze researchers. A team of astronomers has been using Hubble for discovering this group of dwarf galaxies. Scientists have dated the galaxies to be “only 600-900 million years after the big bang.” This might sound like a very big time scale for us, but is very small when compared to the life span of our universe. What makes these galaxies so interesting is not just their age, but also their faintness. NASA told us that the light from the galaxies took around 12 billion years to reach the telescope.

John Richard, an astronomer working on the project said, “The faintest galaxies detected in these Hubble observations are fainter than any other yet uncovered in the deepest Hubble observations.” The Hubble data is being used by the scientists to study the universe’s early stages. Back in time long ago, the universe was nothing but a thick cloud of hydrogen gas, from which the ultraviolet light couldn’t escape. Slowly this began to clear – this stage is called ‘epoch of reionization’ by the scientists. After it all cleared, the UV light could travel great distances. This phase is called as “the universe becoming transparent to ultraviolet light.”

Some of the galaxies discovered now are expected to be involved in the process. NASA says, “they could be the major actors in keeping the universe transparent.” With this discovery the scientists have been able to determine that the reionization phase came to end after 700 million years of the big bang. The Hubble was started as joint project between the European Space Agency and NASA and isn’t getting any older. Earlier this year, it generated beautiful images of Lagoon Nebula, Twin Jet Nebula and dwarf spiral galaxy. The study on the recent finding of the 250 galaxies will be published in Astrophysical Journal.

Cassini images help scientists predict the presence of global ocean on Enceladus

The Cassini probe is an unmanned spacecraft sent by NASA to the planet Saturn. It is a robotic spacecraft and Cassini is the fourth probe to visit Saturn but the first one to enter its orbit. Cassini has been sent to study the planet and its many natural satellites. It has been sending back valuable information and as of now is still transmitting. Using the pictures sent by Cassini to NASA, the researchers have detected and tracked a slight wobble in Saturn’s moon Enceladus. They have determined that the sub-surface body of water on the Saturn moon Enceladus must be far more extensive than they previously thought.

After studying it for around seven years, they have determined that this flutter would be much less if the icy crust was connected directly to Enceladus’s rock core. This can be viewed as a strong support for the idea of an intervening, global mass of liquid. Matthew Tiscareno, a Cassini scientist based at the Seti Institute but previously affiliated to Cornell University, US said,” If the surface core were rigidly connected, the core would provide so much dead weight that the wobble would be far smaller than what we observe it to be. This proves that there must be a global layer of fluid separating the surface from the core.”

Scientists noticed something strange on Enceladus when they first detected the deflection in the disturbance of magnetic fields produced by the presence of something that appeared to be an atmosphere. They quickly established that the moon has huge jets of water vapor through south polar surface cracks dubbed tiger stripes because of their similarity to the big cat’s fur coat. Following this, models were produced to explain how liquid water could be maintained on a 500km- wide body in the outer Solar System, and how it might be feeding the jets.

Other researchers also suggest that Enceladus has the kind of geological activities that are necessary for the evolution of life. This is something that sets it apart from the other moons in our Solar system that seem to have oceans hiding beneath their ice cover. As the scientists are quite certain that Enceladus’s ocean covers the moon’s entire surfaces, the potential habitability of the world has gone way up. This is a major step towards understanding Saturn and its moons. The study has also opened up debate as to why the ocean on the surface of Enceladus not frozen.

Oldest and Farthest Galaxy Discovered by Caltech Scientists

A team of researchers at Caltech has put years of efforts studying the universe and looking for its oldest objects and has stumbled up on the most farthest and perhaps the oldest galaxy ever found – called EGS8p7. The article about the discovery was published in Astrophysical Journal Letters with Adi Zitrin and Richard Ellis. Richard Ellis is Caltech’s recent retiree and Adi Zitrin is a NASA postdoctoral scholar. The galaxy EGS8p7 is estimated to be 13.2 billion years old and the universe itself is 13.8 billion years old. The galaxy was selected as a candidate for investigation based up on data recorded by the Hubble and Spitzer Space telescope. The MOSFIRE (multi-object spectrometer for infrared exploration) was used by the researchers for determining the galaxy’s redshift at Hawaii’s W.M. Keck Observatory. MOSFIRE is capable of detecting chemical signatures of distant galaxies as well as stars at infrared wavelengths.

This involves analyzing the color shift of the light that happens because of the Doppler Effect. The Doppler Effect is responsible for dropping of a truck siren’s pitch as it passes away. However, in the case of planetary objects instead of sound, the light stretches and shifts to the side of red wavelengths. When observing the very early objects, the Redshift is of little use and is often used for measuring the distance to galaxies. After the Big Bang took place, universe was but a cluster of charged particles. The early universe wasn’t capable of transmitting light since the free electrons scattered the photons. The universe cooled down after the 380,000 years allowing combining of free protons and electrons and thus capable of transmitting light.

It is almost certain that the EGS8p7 is very old but it has some light signatures that are putting the researchers in to confusion that such an old galaxy doesn’t emit such bright light. The reason might be that there was a lot of neutral hydrogen in the early universe. Neutral hydrogen absorbs the emitted light of stars and the light wasn’t able to pass for a billion years. Another theory put forward to account for the galaxy’s bright light is that in its core there are extremely hot stars. So the earliest galaxies were formed reionizing the neutral gas just when the universe was half a billion years old. Today the universe remains ionized. Before reionization, radiation of new galaxies called Lyman-alpha line would have been absorbed by the neutral hydrogen. This is the usual indicator of star formation.

Zitrin says, “If you look at the galaxies in the early universe, there is a lot of neutral hydrogen that is not transparent to this emission. We expect that most of the radiation from this galaxy would be absorbed by the hydrogen in the intervening space. Yet still we see Lyman-alpha from this galaxy.”

Ellis says, “The surprising aspect about the present discovery is that we have detected this Lyman-alpha line in an apparently faint galaxy at a redshift of 8.68, corresponding to a time when the universe should be full of absorbing hydrogen clouds.” Before this discovery, the farthest redshift detected was of 7.73.

Astronomers discovered smallest super massive black hole in space

The astronomers have discovered a tiny super-massive black hole. The name of the discovery might come off as a bit of a contradiction but that’s the power of black holes. The astronomers using the Magellan II telescope in Chile and NASA’s Chandra X-ray observatory have discovered the smallest super-massive black hole yet. The black hole has been discovered at the center of a dwarf galaxy.

Black holes are the points in space where gravity has become so extreme that its magnitude exceeds any other forces present in the space. Black holes were called such because not even light can escape from them and that is why it appears to be black. They can appear in two main types: the stellar mass and the super-massive black holes. The stellar mass are mainly formed by the remains of the dead stars that were several times the mass of the sun and the super-massive black holes are the ones that sit at the center of galaxies and can weigh millions or even billions of solar masses.

Apart from this many things about black holes are already known such as, their formation process, different sizes etc. These new findings were published by the Astrophysical letter and could help other scientists in the better understanding of the Universe and how it was created and where it is going. It could also help them to understand the evolution of some the early galaxies with black holes at their center.

The newly found black hole has been named RGG 118 and it appears to have less mass than was expected. The black hole is said to hold a mere 50,000 suns worth of mass. This could sound a bit uncommon but the scientists said that black holes of this mass are quite common. The study’s lead author, Elena Gallo, an astrophysicist at the University of Michigan said,” Most galaxies are fairly small- and whereas we are fairly convinced that there is a black hole sitting at the center of every big galaxy, we’re not sure whether that’s the case in the small ones. It’s just harder to find them, so that’s why we really don’t know.”

Since the RGG 118 is itself in a tiny galaxy it would be safe to assume that it never merged with other galaxies to make the structures that we see in the space these days. The focus now shifts on using the results of this discovery for further research.

Scientists find a galaxy 13.2 billion light years from Earth

The Universe is infinite and millions of galaxies reside in it. So far, we’ve seen able to identify only a few of them and up to a specific distant. Well, now the scientists have found a new galaxy that is roughly 13.2 billion light years away from the Earth. This galaxy has become the farthest one to be recognized by us humans yet. However, the record for the farthest galaxy being found was set in May this year. Both of these were discovered by the twin telescopes of Keck Observatory in Mauna Kea, Hawaii. The Universe is thought to be born 13.8 billion years ago because of the big bang. The discovery of this galaxy now means that the light from this galaxy must have taken 13.2 billion years to reach the Earth. The new found galaxy has been named EGYS8p7 and it is believed that it must have started just 600 million years after the formation of the Universe.The other one, EGS-zsy8-1 was found in May and is said to be 13 billion light years away.The increasing rate in the findings of new galaxies and other heavenly bodies can be attributed to the fact that the telescopes and other instruments have improved over time and better searches can be carried out through them.

The scientists captured an image of hydrogen emission from the galaxy which is a very rare event. This discovery will also help the scientists to understand how the stars initially lit up after the Big Bang. California Institute of Technology astronomer, AdiZitrin, who is also the lead author of the research paper said,” We frequently see the Layman –Alpha emission line of hydrogen in nearby objects as it is one of the most reliable tracers of star-formation. However, as we penetrate deeper into the Universe, the space between galaxies contains a increasing number of dark clouds of hydrogen which absorbs this signal.”

Through computer simulation the researchers have been able to suggest that the Universe was full of hydrogen gas in the first 400 million years of cosmic history. And then gradually, as the first galaxies were born, the intense UV light from the younger stars burnt off the hydrogen in bubbles of increasing radius. The scientists who found the new galaxy have stressed that this discovery will help them a lot and will offer an insight into how some things in the Universe work.


A Dose of Space

  • ISBN: 9781370055241
  • Author: Mohith Agadi
  • Published: 2017-03-23 09:20:08
  • Words: 3697
A Dose of Space A Dose of Space